Can anyone explain to me how you can have RBC in the urine but have the test for blood come up negative? Seems sort of contradictory to me but I am probably misisng something here. Also, how concerned would you be if the lab says the normal RBC is 0-2 and you have a patient who shows up with a 3? I know different labs have different ranges which I still can't understand since I would think lab tests would be standardized. Like the post before this one gave a range of 0-4 HPF while the original post lists the RBC range as 0-2/Hpf. Do you just have to go by what the lab says is the normal range and work from there? Ie you can't compare a urinalysis done at hospital x with another urinalysis done at hospital y?

Can anyone explain to me how you can have RBC in the urine but have the test for blood come up negative? Seems sort of contradictory to me but I am probably misisng something here. Also, how concerned would you be if the lab says the normal RBC is 0-2 and you have a patient who shows up with a 3? I know different labs have different ranges which I still can't understand since I would think lab tests would be standardized. Like the post before this one gave a range of 0-4 HPF while the original post lists the RBC range as 0-2/Hpf. Do you just have to go by what the lab says is the normal range and work from there? Ie you can't compare a urinalysis done at hospital x with another urinalysis done at hospital y?

Females can have blood in urine left over from a period, patient could have had trauma to a kidney, it's basically used as a cut off as being contaminated unless there are any more symptoms that would cause the bleeding (UTI, Kidney stones).

If the value is higher than the range it's usually retested and they will change the test. So if the original was a u/a, then the nest will be a clean catch, or straight cath to prevent contamination.

Every place has it's own cutoffs for lab results. One facility could have 0-6 and the next one is 0-2. This goes for every lab result not just u/a. If or when you go to clinicals at different facilities check the ranges for the tests and you'll see they are different but it's usually not by much.